Field review: Nikon D7100 and Subal ND7100

Wide-angle

As I mentioned earlier, Subal did not send me a dome port or gear for my Tokina 10-17mm, which limited my wide angle photography. Although I was very happy to have the chance to shoot with the Nikon 10.5mm, which remains the best fisheye available for Nikon SLRs, it wasn’t as suited to Balinese subjects at the 10-17mm would have been. That said, visibility was not at its best in the Tulamben area during my stay, and had I not been shooting for a review, I would have probably not shot any wide angle.

I was happy to use the excellent Nikon 10.5mm fisheye again, although it needed to be fitted with a teleconverter to suit many of Bali’s subjects, such as this Rhinopias. Nikon D7100, Nikon 10.5mm, Kenko 1.4x teleconverter. Subal ND7100 housing, Sullivan 6” dome. 2 x Inon Z240 strobes. 1/100th, f/16, ISO 200.

I used the AUTO area autofocus (in AF-C) mode for wide angle, which worked well, except when the sun caught micro scratches in my acryllic dome port and confused it. Despite these occasional problems, I would recommend this focus mode for wide angle on the D7100.
The D7100 also coped well with high dynamic range scenes, such as sunbursts. Despite only limited testing, I felt that that it performed between the D7000 and D800, both of which are excellent in this regard. Although that is what I would have said about the camera before I tried it! Ideally I would have liked more time for more rigorous testing.

I was keen to examine the high ISO performance of the D7100. A camera that squeeses 24 MP on a DX chip (the equivalent of 58MP on full frame sensor) is not typically the recipe for good low light performance. But each generation of cameras continues to make us reassess what we think is possible.

These are 100% crops of the above photos (unsharpened and no noise reduction applied), which, first, show how large the files are that the ND7100 produces. ISO 800 is clearly more noisy than ISO 200, but given the large file size, this level of noise would not be significant in most uses.

The revolutionary Nikon D800 made us reassess how we evaluate at noise in digital cameras. Like the D800, the D7100 shows visible noise as you turn up the ISO, but because of the very high pixel count, this is often not significant when you think of final image use. In short, increasing the ISO on both cameras is not something to be scared of doing, instead, just be aware that the more you turn it up, the smaller the maximum reproduction size of the final image becomes. However, it will probably remain larger than your intended image useage.

These are 50% crops of the above photos which show that ISO 800 is entirely useable and ISO 1600 is good too. At ISO 3200 the level of noise is definitely overcoming the fine detail in the image, but the entire file would still look great on screen of for projection.

If you are coming from a 12MP Nikon, this is a very different way of thinking about high ISO shooting. Noise isn’t really the problem, instead turning up the ISO simply means you’ll need to down-sample the file size to hide the noise. In other words, if you want to use all of that available resolution, then keep the ISO low, but don’t be afraid of using ISO on the ND7100. Even ISO 1600 is usable for most outputs. ISO 3200 does seem to introduce noise at levels that overwhelms fine details, but the files would still be fine for on screen use and for projection. The other impact of high ISO shooting is reduced dynamic range, most obvious as highlights blowing out.

Great review and confirmed I made the right choice as I purchased the D7100 and Nauticam housing with viewfinder mid summer. I upgraded from a D90 and it is like night and day. The sharpness and features are incredible and the housing so far is terrific. The only downside appears to be the limited buffer for above surface e.g. humpback whale shots. Also I still have trouble remembering to flip up the D7100 flash to connect fibre optics strobes and have lost a few good shots that way!

Alex - where would you use the 1.3 exra crop. I assume it does not alter the focal length in any way. I used it once when I had on wide angle and vis was not appropriate and it made a small difference only.

I would not hesitate to recommend this camera as an upgrade from the D90 but then would probably have said the case with the D7000 if I had purchased it.

By the way for my type of fish portrait photography I really recommend the Sigma 17-70 mm lens which is so versatile and does not need a diopter behind the port. I did not buy the latet version as I read a review which said the wide end was better on an older version.

Cheers, Ron

Posted by ronlucasdiver on 2013-12-19 12:41:52

Enjoyed the review Alex, Great timing for me asi am coming up to the time when it is finally time to upgrade my D90. So a lot of the comments and observations that you have made pertain to someone like myself. Also answered a lot of the questions that i had with regards to D7100, D610 and D800. I cannot afford the D800 so that comes right of the list. the D610 down here is about 1000AUD more than the D7100. And when i think about all my likes and dislikes of my D90, resolution actually never comes into my mind; it is always those shots that i missed through the AF missing etc.. and the other issue for me was the shutter sync, 1/200 for sunballs, i could never sort my lighting out to capture truly wonderful sunballs as perhaps D300s could. It is these two points that make me look at the D610 as a great sensor in a budget package. Whereas the D7100 seems to tick all my buttons and i don't have to buy more glass and can get a viewfinder instead :) Cheers.

Posted by alastair on 2013-12-15 15:45:03

@ Rick, I agree that the D600/D610 is a fine (and regularly underrated) camera. Sensor is fantastic, AF lags behind the D7100 and D800 - which are the best DX and FX UW Nikons at the moment. I reviewed the D600 versus the D800 here:

Thom Hogan has some fairly harsh words on the topic, which I actually don't fully agree with, but feel are worth sharing: "Choosing a D610 over a D800 means you're willing to settle for fewer pixels, lower body quality, and fewer AF sensors in order to get a significant discount. In other words, you're a bargain hunter, not someone trying to get the best possible tool."

IMO the D600 sensor is excellent. If I could get it in a D800 body that would be my choice of FX Nikon. And as it is I can see many favouring the D600/D610 because AF, for example, is not critical to their type of underwater photography.

It is why in the reviews I try and explicitly state the areas of underwater photography where there different cameras have their strengths and weaknesses.

p.s. What a pain it is to post here - had to create a DISQUS account just to leave a comment.

Posted by Alex Mustard on 2013-12-15 01:03:47

Extremely useful review! Many thanks!

One question: I was looking for some explanation of the write-off of the D610 as an upgrade path.... where is it? What of the argument that the D610 gives the better high ISO performance of the D800 without the massive file size, or body size and weight, not to mention expense?